-_第1章一、思考题4. （1） B=A(2:5,1:2:5)（2）A(7)=（3） A=A+30（4）size(A)（5） t(find(t=0)=eps（6）t=reshape(x,3,4)（7）abs(matlab)（8）char(93)5. A=97,67,34,10;-78,75,65,5;32,5,-23,-59;0,-12,54,7 (1) B=A(1:3,:) C=A(:,1:2) D=A(2:4,3:4) E=B*C(2)A(find(A=50 & A120 gz=dj*120+1.15*dj*(h-120);elseif h60 gz=dj*h-700;else gz=dj*h;endformat bank;display(gh,gz)3. 循环结构n=input(input n:);s=0;for k=1:n s=s+1/k2;enddisplay(sqrt(s*6)向量运算n=input(input n:);k=1:n;display(sqrt(sum(1./k.2)*6)4.y=0;k=0;while y=1e-5 & k500 x0=x; x=a/(b+x0); k=k+1;enddisplay(k,x);display(-b+sqrt(b2+4*a)/2,(-b-sqrt(b2+4*a)/2);6.y=fun(40)/(fun(30)+fun(20)（1）函数文件fun.mfunction f=fun(n)f=n+log(n2+5);（2）函数文件fun.mfunction f=fun(n)a=1:n;f=sum(a.*(a+1);第3章一、思考题4. t=0:0.01:1.5;y=sqrt(3)/2*exp(-4*t).*sin(4*sqrt(3)*t+pi/3);5. x=-10:0.01:10;y=linspace(-6,6,size(x,2)z=x.3+3*x.*y.2;plot3(x,y,z)6. x=100:100:400;y=100:100:400;z=636,697,624,478;698,712,630,478;680,674,598,412;662,626,552,334;X,Y=meshgrid(x,y);mesh(X,Y,z)二、实验题1. （1）x=-10:0.01:10;plot(x,x-x.3/3/2)（2）plot(x,exp(-x.*x/2)/2/pi)（3）x=-8:0.01:8;plot(x,sqrt(64-x.*x)/2)（4）t=0:pi/100:6*pi;plot(t.*sin(t),t.*cos(t)2. （1）x1=linspace(0,1,100);y1=2*x1-0.5;t=linspace(0,pi,100);x=sin(3*t).*cos(t);y=sin(3*t).*sin(t);plot(x1,y1,r-,x,y,b:);text(0.4,1,y=2x-0.5);text(-0.4,0.5,x=sin(3t)cos(t);text(-0.4,0.3,y=sin(3t)sin(t);（2） subplot(1,2,1);scatter(x1,y1,10) title(y=2x-0.5);subplot(1,2,2);scatter(x,y,10)3. subplot(1,2,1); x=1:1:100; y=sin(1./x);plot(x,y)subplot(1,2,2);fplot(sin(1/x),1,100)4. subplot(2,2,1);bar(t,y);subplot(2,2,2);stairs(t,y);subplot(2,2,3);stem(t,y)subplot(2,2,4);semilogy(t,y);5. theta=linspace(-pi,pi,100);ro=5.*cos(theta)+4;polar(theta,ro);fi=linspace(0,2*pi,100);a=1r=a.*(1+cos(fi);polar(fi,r);6. t=0:pi/20:2*pi;x=exp(-t./20).*cos(t);y=exp(-t./20).*sin(t);z=t;plot3(x,y,z);t=0:0.01:1;x=t;y=t.2;z=t.3;plot3(x,y,z);7. x=-30:0.1:0;y=0:0.1:30;x,y=meshgrid(x,y);z=10.*sin(sqrt(x.2+y.2)./sqrt(1+x.2+y.2);meshc(x,y,z);8. x=linspace(-3,3,100);y=linspace(-3,3,100);x y=meshgrid(x,y);fxy=-5./(1+x.2+y.2);i=find(abs(x)=0.8 & abs(y)=0.5);fxy(i)=NaN;surf(x,y,fxy)9. u=linspace(1,10,100);v=linspace(-pi,pi,100);u,v=meshgrid(u,v);x=3.*u.*sin(v);y=2.*u.*cos(v);z=4*u.2;x=3*u.*sin(v);y=2*u.*cos(v);z=4*u.2;surf(x,y,z);shading interp;light(position,1,0,1);10. t=0:pi/100:2*pi;y=sin(t);comet(t,y)第4章一、思考题5.（1）A=eye(3);（2）C=100+(200-100)*rand(5,6);（3）D=1+sqrt(0.2)*randn(1,500);（4）E=ones(size(A);（5）A=A+30*eye(size(A);（6）B=diag(diag(A)二、实验题1. P=pascal(5);H=hilb(5);Dp=det(P);Dh=det(H);Kp=cond(P);Kh=cond(H);P矩阵的性能更好，因为Kp较小2.A=1,-1,2,3;0,9,3,3;7,-5,0,2;23,6,8,3B=3,pi/2,45;32,-76,sqrt(37);5,72,4.5e-4;exp(2),0,97A1=diag(A);B1=diag(B);A2=triu(A);B2=triu(B);A3=tril(A);B3=tril(B);rA=rank(A);rB=rank(B);nA=norm(A);nb=norm(B);cA=cond(A);cB=cond(B);3. A=31,1,0;-4,-1,0;4,-8,-2；V,D=eig(A);4. A=diag(-1,-1,-1,-1,-1)+diag(-1,-1,-1,-1,1)+diag(2